Smoke control device



NOV- 24 1931- F. P. BIEDERWOLF SMOKE CDNTROL DEVICE Filed July 19. 1929 Patented Nov. 24, 1931 UNITED STATES FRED P. BIEDERWOLF, OF MONTICELLO, INDIAN SMOKE CONTROL` DEVICE Application filed my 19,

This invention relates to means for eliminating smoke from chimneys, stacks and the like, and particularly to means for automatically regulating` the amount of air passing over the top of a tire within a fire-box.

In tiring furnaces, particularly in Vresidences where the lire-box is charged intermittently and an attendant is not regularly stationed at the furnace, the common practice is to shovel in a quantity of coal sufficient to last over a considerable interval of time so that the actual periods of firing may be spread apart as far as may be possible in maintaining a fire, with the result that, when the new supply of coal is put in the fire-box,

the bed oflive coals is completely covered over with a layer of coal of sufficient depthl to eiiectually cut off air passages therethrough until the `hre below may burn holes to let air entering from below the lire bed to pass up through and supply the necessary amount of oxygen required for combustion.

In other words, the normal draft of air from below the fire and on into the stack is '2 temporarily checked until the fire can eat up through the green coal. W'hile this process of readjustment is taking place, large quantities of smoke and gas are passing out the stack. Sufiicient air is not supplied over the top of the coal to support combustion of the gaseous products being driven ofi from the coal by the fire below.

It is the primary purpose of my invention to provide means whereby air may automatically be supplied above the fire bed at each structure requiring no further attention after installation; and that may be produced and installed at a very low cost.

I accomplish these and other objects as t will become apparent in the following de 1929. yseran No. 379,367.

scription of the device as shown in the ac- Y companying drawings in which Fig. 1 is a front elevation of a fire-box door with my invention applied thereto;V

Fig. 2, a. vertical section on the line 2-2 in Fig. 1;

F ig. 3, a horizontal 3 3 in Figzl; and

Fig. 4, a rear elevation of the door as shown in Fig. 1.

Like characters of reference indicatelike parts'throughout the several views in the drawings.

' T he door 10 here shown is the usual door on afurnace (not shown) through which coal is supplied to replenish the lire, the door 10, being therefore, the one above the lire bed. I form a frame 11, preferably of angle iron and mount it in the door in place of the usual section on the line slide damper (not shown) employed in such doors. The frame 11 is employed to support` a number of .slats here shown as three in number consisting' of the slats-12, 13, and 14 roclably secured in the Yframe by the pins 15 and capable of being revolved thereabout on parallel horizontal axes.

`Each of the slats 12, 13, and 14 are the same in shape and have an S-shape in cross section (Fig. 2). The pins 15 project from the ends of the slats on an axis slightly above the centers of gravity of the slats so that each slat normally tends to Vrock by its pins 15 in the frame to hang vertically disposed, as vshown'in Fig. 2, where the rearwardly projecting upper lip of one slat will extend over and contact the forward face of the forwardly projecting` lower'lip of the next above slat to form a seal therebetween. Lips 16 and 1T are provided in the frame as stops for the slats 12 and 14.

Immediately back of the front of the door to which theframe 11 is attached, is the usual baille plate 18 with an air space therebetween. The plate 18 is provided with a plurality of holes 19 therethrough preferably increasing inv'size from top to bottom whereby most of, the air passing through the plate 18 will pass through the lower holes 19 nearer the bed of iire tlierebehind. Y Y

Normally, the slats 12, 13, and 14 will hang in the closed position as shown by the solid rows of holes therethrough, which holes inlines in Fig. 2, when the fire behind the door crease in size from the top row to the bottom is burning freely With the lower draft door row.

(not shown) open to allow air to pass up through the fire bed. New when the bed is covered with a fresh supply of coal, the nornial draft through the bed is checked, so that a slight vacuum in the fire-box above the coal is produced and Will cause air to be pulled against the slats 12, 13 and 14 with the result that the sl ts, being nearly balanced on the pins 15 (being out of balance just enough to insure closure under normal lire conditions), will be rocked by the air pressing against the slightly longer sections below the pins 15 to cause the slats to be rocked open as indicated by the dotted lines to let a current of air pass thereover against the plate 18 and be diffused through the holes 19 on over and above the fire bed.

is a further aid to diffusion of the incoming air, the lower edges of the slats, Fig. 1, may be serrated, by having teeth 2() formed therealong, normally covered by the upper lip of the slat therebelow.

As soon as air again starts coming through the tire bed the partial vacuum thereabove is reduced so that the slats 1Q, 13, and 14 may again drop to their normal closing positions, and the excess air theretofore entering to sup-port combustion above the coal is shut off and the normal draft functions as before.

I claim:

1. The combination of a fire door having an opening therethrough, of a plurality of slats, S-shaped in cross-section and pivotally mounted on horizontal axes, said aXes being slightly above the centers of gravity of the respective slats, and being so karranged that each slat contacts at one edge with an adjacen-u slat by the action of gravity to close said opening, said slats being mounted so that each may swing independently of the others `to open posit-ion under the influence of air pressure on the outer face thereof, and each having a serrated edge overlapped by an adjacent part when the slats are in closed position.

2. The combination of a fire door having an opening therethrough, of a plurality of slats, S-shaped in cross-section and pivotally mounted on horizontal axes, said axes being slightly above the c nters of gravity of the respective slats, and being so arranged that each slat contacts at one edge with an adjacent sl at by the action of gravity to close said opening, said slats beingl mounted so that each may swing independently of the others to open position under the influence of air pressure on the outer face thereof, and each having a` serrated edge overlapped by an adjacent part when the slats are in closed position, and a baille plate carried by the door spaced behind the slats having a plurality of horizontal In testimony whereof I atlix my signature.

FRED P. BIEDERWOLF. 

